IQ: IQ is an abbreviation for " intelligence quotient, a measure of a person's intellectual ability in relation to that of the rest of the population. It is expressed as the ratio of mental age to actual age, multiplied by 100, and is based on the scores achieved in an intelligence test. the two most important scales for measuring IQ are the Standford-Binet test and the Weschler test. The distribution ofIQ scores is more-or-less Gaussian, that is to say that it follows the bell curve.• IQ: IQ is an abbreviation for “intelligence quotient”, a measure of a person's intellectual ability in relation to that of the rest of the population. It is expressed as the ratio of mental age to actual age, multiplied by 100, and is based on the scores achieved in an intelligence test. The two most important scales for measuring IQ are the Standford-Binet test and the Weschler test. The distribution of IQ scores is more-or-less Gaussian, that is to say that it follows the bell curve